List of the Paleozoic life of Iowa

This list of the Paleozoic life of Iowa contains the various prehistoric life-forms whose fossilized remains have been reported from within the US state of Iowa and are between 538.8 and 252.17 million years of age.

• †Abatocrinus
• †Acidaspis
• †Aclisina

• 

  †Actinocrinites
  • †Actinocrinites gibsoni
  • †Actinocrinites jugosus
  • †Actinocrinites lowei
  • †Actinocrinites pernodosus
  • †Actinocrinites probolos
• †Actinopteria – tentative report
• †Actinostroma
  • †Actinostroma clathratum
• †Acutatheca
  • †Acutatheca propira
• †Adocetocystis
• †Adolfia
• †Aechmina
  • †Aechmina cuspidata
  • †Aechmina ionensis
  • †Aechmina maquiketensis
  • †Aechmina taurea
• †Agassizodus
  • †Agassizodus variabilis
• †Agelacrinites
• †Aglaocrinus
  • †Aglaocrinus compactus
• †Allanella
  • †Allanella allani
  • †Allanella annae
  • †Allanella cardinalis
• †Allenella
  • †Allenella allani
  • †Allenella annae
• †Allocrinus
  • †Allocrinus ornatus
  • †Allocrinus subglobosus
• †Allorhynchus
  • †Allorhynchus currei – or unidentified comparable form
• †Allozygocrinus
  • †Allozygocrinus dubuquensis
• †Alveolites
• †Ambocoelia
  • †Ambocoelia louisianaensis
  • †Ambocoelia minuta
• †Ambonychia
• †Americoncha
  • †Americoncha marginata
• †Amphicoelia
• †Amphicyrtoceras
• †Amphipora
  • †Amphipora pervesiculata
• †Amplexus
• †Anartiocystis
• †Anastrophia
• †Anataphrus
• †Anematina
  • †Anematina conica
• †Angyomphalus
  • †Angyomphalus lens
  • †Angyomphalus penelenticulata – type locality for species
• †Anisotrypa
• †Anomphalus
• †Anthracospirifer
  • †Anthracospirifer pellaensis
• †Antiquatonia
• †Antirhynchonella
• †Antirotella
  • †Antirotella kindlei – type locality for species
• †Aorocrinus
• †Aparchites
  • †Aparchites barbatus
  • †Aparchites carinatus
  • †Aparchites chatfieldensis
  • †Aparchites ellipticus
  • †Aparchites fimbriatus
  • †Aparchites macrus
  • †Aparchites paratumida
• †Aphelecrinus
• †Apycnodiscus
• †Arabellites
• †Arachnophyllum
• †Archaeocalyptocrininus
  • †Archaeocalyptocrininus iowensis
  • †Archaeocalyptocrininus nodosus
• †Archaeocalyptocrinus
  • †Archaeocalyptocrinus iowensis
  • †Archaeocalyptocrinus nodosus
• †Archaeocrinus
  • †Archaeocrinus obconicus
• †Archaeogastropod
• †Archinacella
  • †Archinacella rotunda

• 

  †Arctinurus
• †Arctomeristina
• †Arisaigia
• †Arrectocrinus
  • †Arrectocrinus iowensis
• †Arthroxylon
• †Asphaltinella
• †Asterophyllites
  • †Asterophyllites multifolia
• †Asthenophyllum
• †Astraeospongium
• †Astreptodictya
• †Astrocystites
  • †Astrocystites ottawaensis – tentative report
• †Atelodictyon
  • †Atelodictyon masoncityense – type locality for species
• †Athyris
  • †Athyris cedarensis
  • †Athyris crassicardinalis
  • †Athyris fultonensis – or unidentified comparable form
  • †Athyris simplex
  • †Athyris spiriferiodes
  • †Athyris vitatta
  • †Athyris vittata
  • †Athyris zonulata
• †Atribonium
  • †Atribonium nora
  • †Atribonium paupera
  • †Atribonium prolifica
  • †Atribonium subovata
  • †Atribonium swallovi
• †Atrypa

  • 

    †Atrypa reticularis
  • †Atrypa reticularus
• †Atryparia
  • †Atryparia varicostata
• †Atrypoidea
• †Aulacella
• †Aulocopella
  • †Aulocopella dactylos – type locality for species
  • †Aulocopella probolos – type locality for species
  • †Aulocopella scelidos – type locality for species
• †Aviculopecten
  • †Aviculopecten marbuti – or unidentified comparable form

• Bairdia
• †Bairdiocypris
  • †Bairdiocypris granti
• †Bairdocypris
  • †Bairdocypris granti
• †Basseleratia
  • †Basseleratia typa
• †Bassleratia
  • †Bassleratia typa
• †Batostomella
• †Baylea
  • †Baylea trifibra – type locality for species
• †Beecheria
  • †Beecheria chouteauensis
• †Belemnocrinus

• 

  †Bellerophon
  • †Bellerophon blairi
  • †Bellerophon panneus
  • †Bellerophon patersoni
  • †Bellerophon vinculatus
• †Bellornatia
  • †Bellornatia tricollis
• †Belodina
  • †Belodina compressa
• †Beloitoceras – tentative report
  • †Beloitoceras discrepana
• †Bembexia
  • †Bembexia minima
• †Bensbergia
  • †Bensbergia pulchra – type locality for species
• †Beyrichia
  • †Beyrichia irregularis
• †Bighornia
• †Blothrocrinus
• †Bobbodus
  • †Bobbodus schaefferi
• †Bolicrinus
  • †Bolicrinus deflatus
  • †Bolicrinus globosus
• †Bollia
  • †Bollia regularis
  • †Bollia ruthae
  • †Bollia subaequata

• 

  †Bothriocidaris
  • †Bothriocidaris maquoketensis
• †Botryocrinus
  • †Botryocrinus thomasi – type locality for species
• †Brachythyris
  • †Brachythyris burlingtonensis – or unidentified comparable form
  • †Brachythyris chouteauensis
  • †Brachythyris peculiaris
• †Brachytomaria
  • †Brachytomaria semele
• †Breviphillipsia
• †Brockocystis
  • †Brockocystis nodosaria
• †Bromidella
  • †Bromidella depressa
  • †Bromidella rhomboides
• †Bryantodina
  • †Bryantodina typicalis
• †Bucanella
  • †Bucanella conradi
• †Bucanopsis
  • †Bucanopsis lirata
• †Bullatekka
  • †Bullatekka granilabiatus
• †Bullatella
  • †Bullatella granilabiatus

• 

  †Bumastus
• †Buranella
• †Buxtonia – tentative report
• †Byrsolopsina
  • †Byrsolopsina centipunctata
  • †Byrsolopsina normella
  • †Byrsolopsina ovata
  • †Byrsolopsina planilateralis
• Bythocypris
  • †Bythocypris curta
  • †Bythocypris furnishi

• †Caenanoplia
  • †Caenanoplia logani
• †Calamocarpon
  • †Calamocarpon insignis
• †Calceocrinus
  • †Calceocrinus levorsoni
• †Calcisphaera
  • †Calcisphaera laevis
• †Calliocrinus
  • †Calliocrinus longispinus
• †Callocrinus
  • †Callocrinus longispinus
• †Callocystites
• †Calvinaria
  • †Calvinaria ambigua
  • †Calvinaria bransoni
• †Calvustrigis – tentative report

• 

  †Calymene
• †Camarophorella
  • †Camarophorella lenticularis
• †Camarotoechia
  • †Camarotoechia chemungensis
  • †Camarotoechia chouteauensis
  • †Camarotoechia crassiplicata
  • †Camarotoechia perplexa
  • †Camarotoechia quadricostatum
  • †Camarotoechia saxatilis
  • †Camarotoechia saxatillis
  • †Camarotoechia tuta
• †Camerella
• †Carabocrinus
  • †Carabocrinus radiatus
  • †Carabocrinus slocomi
• †Cardiola
  • †Cardiola lyoni
• †Carinatrypa
  • †Carinatrypa dysmorphstrota
• †Cariniferella
  • †Cariniferella iowensis
• †Carpocrinus
  • †Carpocrinus bodei
• †Caryocrinites

• 

  †Catenipora
• †Ceratocephala
• †Ceratopsis
  • †Ceratopsis humilinoda
  • †Ceratopsis quadrifida
  • †Ceratopsis trilobis
• †Ceraurus
• †Cerithioides
  • †Cerithioides judiae
• †Characterophyllum
  • †Characterophyllum nanum
• †Charactoceras
• †Charactophyllum
  • †Charactophyllum nanum
• †Charionella
  • †Charionella nortoni

• 

  †Cheirurus
• †Chomatodus
  • †Chomatodus inconstans
• †Chonetes
  • †Chonetes glenparkensis
  • †Chonetes illinoisensis
  • †Chonetes logani
  • †Chonetes multicosta
  • †Chonetes multicostata
  • †Chonetes ornatus
• †Chonetina
• †Chonetinella
• †Chonetipustula
  • †Chonetipustula concentrica
• †Chonopectus
  • †Chonopectus fischeri
• †Chonophyllum
• †Clathrocoilona
  • †Clathrocoilona involuta – type locality for species
• †Clathrodictyon
• †Cleiocrinus
  • †Cleiocrinus regius
• †Cleiothyridina
  • †Cleiothyridina crassicardinalis – or unidentified related form
  • †Cleiothyridina glenparkensis – or unidentified comparable form
  • †Cleiothyridina incrassata – or unidentified comparable form
  • †Cleiothyridina sublamellosa
• †Climacoconus
  • †Climacoconus pumilus

• 

  †Climacograptus
  • †Climacograptus pumilis
  • †Climacograptus typicalis
• †Clinolithes
• †Clinopistha
• †Clintonella – tentative report
• †Clorinda
• †Cochliodus
  • †Cochliodus occidentalis
• †Coelospira
• †Coeloterorhynchus
  • †Coeloterorhynchus schucherti
  • †Coeloterorhynchus subacuminata
  • †Coeloterorhynchus subacuminatus
• †Coenites
• †Composita
  • †Composita humilis – tentative report
  • †Composita immatura – or unidentified comparable form
  • †Composita trinuclea
• †Compsocrinus
• †Concavicaris
  • †Concavicaris sinuata – or unidentified comparable form
• †Conocardium
• †Conotreta
• †Conularia
• †Coolinia

• 

  †Cornulites
• †Costistricklandia
  • †Costistricklandia castellana
  • †Costistricklandia multilirata
• †Cotylacrina
  • †Cotylacrina sandra
• †Cranaena
  • †Cranaena amana
  • †Cranaena arcuosa
  • †Cranaena calvini
  • †Cranaena depressa
  • †Cranaena elia
  • †Cranaena famelica
  • †Cranaena inflata
  • †Cranaena infrequens
  • †Cranaena iowensis
  • †Cranaena jacunda
  • †Cranaena lata
  • †Cranaena littleonensis
  • †Cranaena littletonensis
  • †Cranaena maculata
  • †Cranaena marsii
  • †Cranaena micula
  • †Cranaena navicella
  • †Cranaena occidentalis
  • †Cranaena pachytesta
  • †Cranaena parvirostra
  • †Cranaena rhomboidialis
  • †Cranaena rockfordensis
  • †Cranaena romingeri
  • †Cranaena seminula
  • †Cranaena subcylindrica
  • †Cranaena subglobosa
  • †Cranaena subglossa
  • †Cranaena subgobulosa
  • †Cranaena subouata
  • †Cranaena subovata
  • †Cranaena thomasi
• †Cranaenella
• †Crania
  • †Crania famelica
• †Crassiproetus
  • †Crassiproetus arietinus
  • †Crassiproetus bumastoides
  • †Crassiproetus occidens
  • †Crassiproetus searighti
• †Cremacrinus
  • †Cremacrinus gerki
  • †Cremacrinus guttenbergensis
  • †Cremacrinus punctatus – or unidentified related form
  • †Cremacrinus type locality for species – informal
• †Cribanocrinus
• †Crotalocrinintes

• 

  †Crotalocrinites
• †Crurithyris
• †Cryptophyllus
  • †Cryptophyllus oboloides
  • †Cryptophyllus sulcatus
• †Ctenobolbina
  • †Ctenobolbina emaciata
  • †Ctenobolbina maquoketensis
• †Ctenodonta
  • †Ctenodonta anatina
  • †Ctenodonta calvini
• †Cupularostrum
  • †Cupularostrum contracta
  • †Cupularostrum saxatilis
  • †Cupularostrum saxatillis
• †Cupulocorona
• †Cupulocrinus
  • †Cupulocrinus angustatus
  • †Cupulocrinus conjugans – or unidentified related form
  • †Cupulocrinus crossmani
  • †Cupulocrinus latibrachiatus – or unidentified related form
• †Curtognathus
• †Cusacrinus
• †Cyathaxonia
  • †Cyathaxonia arcuatus

• 

  †Cyathocrinites
• †Cyathocrintes
  • †Cyathocrintes striatissimus – or unidentified comparable form
• †Cyathophyllum
• †Cyclocrinites
  • †Cyclocrinites dactilioides
  • †Cyclocrinites dactioloides
• †Cyclocystoides
• †Cyclonema
  • †Cyclonema bilix
  • †Cyclonema minuta
• †Cyclora
• †Cynopodius
• †Cyphaspis
• †Cypricardella
• †Cypricardinia
  • †Cypricardinia sulcifera
• †Cyrtia
  • †Cyrtia exporrecta
• †Cyrtina
  • †Cyrtina inulta
  • †Cyrtina iowaensis
  • †Cyrtina triquetra
  • †Cyrtina umbonata
• †Cyrtodonta
• †Cyrtolites
• †Cyrtospira

• 

  †Cyrtospirifer
  • †Cyrtospirifer disjunctus
  • †Cyrtospirifer whitneyi
• †Cystiphyllum
  • †Cystiphyllum mundulum
• †Cystodictya
• †Cytocrinus

• †Dalejina
• †Dalmanella
  • †Dalmanella edgewoodensis – or unidentified comparable form

• 

  †Dalmanites
• †Dapsilodus
  • †Dapsilodus mutatus
• †Dawsonoceras
• †Decadocrinus
  • †Decadocrinus crassidactylus – type locality for species
  • †Decadocrinus pachydactylus – type locality for species
  • †Decadocrinus spinulifer – type locality for species
• †Decaschisma
• †Dechenella
  • †Dechenella haldemani – or unidentified comparable form
  • †Dechenella nortoni
  • †Dechenella prouti
  • †Dechenella rowi – or unidentified comparable form

• 

  †Deiphon
• †Delocrinus
  • †Delocrinus vulgatus
• †Deltaherpeton – type locality for genus
  • †Deltaherpeton hiemstrae – type locality for species
• †Delthyris – tentative report
• †Deltodus
  • †Deltodus spatulatus
• †Dendrocrinus
  • †Dendrocrinus casei
  • †Dendrocrinus curvijunctus – or unidentified related form
  • †Dendrocrinus oswegoensis

• 

  †Dentalium
  • †Dentalium grandaevum
• †Derbyia
• †Desquamatia
  • †Desquamatia brandonensis
  • †Desquamatia independensis
  • †Desquamatia randalia
  • †Desquamatia rotunda
  • †Desquamatia rusica
  • †Desquamatia scutiformis
  • †Desquamatia waterlooensis
• †Devonatrypa
  • †Devonatrypa brandonensis
  • †Devonatrypa pronis
  • †Devonatrypa trowbridgei
  • †Devonatrypa waterlooensis
• †Devonochonetes
  • †Devonochonetes calivini
• †Devonoproductus
  • †Devonoproductus reticulocostus
  • †Devonoproductus vulgaris
  • †Devonoproductus walcotti
• †Diamphidiocystis
• †Diceromyonia
• †Dichacaenia
  • †Dichacaenia harberti
• †Dichocrinus
• †Dicoelosia
• †Dicranella
  • †Dicranella bicornis
  • †Dicranella marginata
  • †Dicranella simplex
  • †Dicranella spinosa
  • †Dicranella typa
• †Dicranopeltis
• †Dictyoclostus
• †Dictyotomaria
  • †Dictyotomaria quasicapillaria – type locality for species
• †Dielasma
  • †Dielasma burlingtonensis
  • †Dielasma chouteauensis
  • †Dielasma formosum
• †Dimerocrinites
  • †Dimerocrinites hopkintonensis
  • †Dimerocrinites pentangularis
  • †Dimerocrinites sculptus
• †Dinobolus
• †Dinolobus
• †Dinorthis
• †Diopatraites
• †Diphyphyllum
• †Diploblastus
  • †Diploblastus glaber

• 

  †Diplograptus
  • †Diplograptus modestus – or unidentified comparable form
• †Diplophyllum
• †Diplosphaerina
  • †Diplosphaerina inaequalis
• †Discosorus
• †Disphyllum
  • †Disphyllum conjugans – type locality for species
  • †Disphyllum dispassum
  • †Disphyllum floydense
  • †Disphyllum iowensis – type locality for species
  • †Disphyllum tubiforme
• †Dolerorthis
• †Donaldina – tentative report
• †Dorycrinus
  • †Dorycrinus gouldi
  • †Dorycrinus mississippiensis
• †Douvillina
  • †Douvillina arcuata
  • †Douvillina cayuta
  • †Douvillina delicata
  • †Douvillina distans
  • †Douvillina maxima
  • †Douvillina navicula
  • †Douvillina oxycostratum
  • †Douvillina variabilis
• †Douvillinaria
  • †Douvillinaria delicata
  • †Douvillinaria perversa
  • †Douvillinaria variabilis
  • †Douvillinaria variablis
• †Drepanoistodus
  • †Drepanoistodus suberectus
• †Dudleyaspis
• †Dvorakia
  • †Dvorakia chattertoni – type locality for species

• †Earlandia
• †Ecclimadictyon
  • †Ecclimadictyon fastigiatum
• †Echinocoelia
  • †Echinocoelia halli
• †Echinoconchus
• †Ectenocrinus
  • †Ectenocrinus raymondi
  • †Ectenocrinus simplex
• †Ectodemites
  • †Ectodemites primus
• †Ectogrammysia
  • †Ectogrammysia hannibalensis

• 

  †Edestus
  • †Edestus crenulata
  • †Edestus mirus – type locality for species
• †Edmondia
  • †Edmondia jejunus
• †Eldredgeops
  • †Eldredgeops rana
• †Eleutherokomma
  • †Eleutherokomma jasperensis
• †Elita
  • †Elita diversa
  • †Elita inconsueta
  • †Elita johnsonensis
  • †Elita minor
  • †Elita subundifera
  • †Elita urbana
• †Ellesmeria
  • †Ellesmeria scobeyi
• †Ellesmeroceras
  • †Ellesmeroceras luthei
  • †Ellesmeroceras thomasi
• †Emanuella
  • †Emanuella ii – report made of unidentified related form or using admittedly obsolete nomenclature
  • †Emanuella meristoides
  • †Emanuella sublineata
• †Emphereaster
  • †Emphereaster missouriensis
• †Encrinurus

• 

  †Endoceras
• †Endostaffella
  • †Endostaffella discoidea
• †Endothyra
  • †Endothyra obsoleta – tentative report
• †Endothyranella
• †Enoploura
  • †Enoploura wetherbyi
• †Enteletes
• †Entelophyllum
• Eocaudina
  • †Eocaudina septaforaminalis – type locality for species
• †Eochonetes
  • †Eochonetes aspera
  • †Eochonetes dignata – type locality for species
  • †Eochonetes recedens
• †Eodictyonella
• †Eolissochonetes
• †Eomartiniopsis
  • †Eomartiniopsis rostrata
• †Eoparisocrinus
  • †Eoparisocrinus crossmani
• †Eophacops
• †Eoplectodonta
• †Eoschmidtella
  • †Eoschmidtella umbonata
• †Eospirifer
  • †Eospirifer radiatus
• †Eospirigerina
  • †Eospirigerina putilla – or unidentified comparable form
• †Eostrophalosia
  • †Eostrophalosia independensis
  • †Eostrophalosia inexpectans
  • †Eostrophalosia rockfordensis
• †Eosyringothyris
  • †Eosyringothyris aspera
  • †Eosyringothyris occidentalis
  • †Eosyringothyris thomasi
  • †Eosyringothyris triangularis
• †Ephippiorthoceras
• †Eridoconcha
  • †Eridoconcha gibbera
  • †Eridoconcha punctata
• †Eridotrypa
• †Erismacanthus
  • †Erismacanthus barbatus
• †Erismodus
  • †Erismodus radicans
• †Escharopora

• 

  †Eucalyptocrinites
  • †Eucalyptocrinites depressus
  • †Eucalyptocrinites inornatus
  • †Eucalyptocrinites ornatus – or unidentified comparable form
  • †Eucalyptocrinites proboscidalis
• †Eukloedenella
  • †Eukloedenella richmondensis
• †Eumetria
  • †Eumetria iowensis
  • †Eumetria osagensis
• †Eumorphocystis
• †Eunema
  • †Eunema quadrisulcata

• 

  †Euomphalus
  • †Euomphalus angularis
  • †Euomphalus obtusus
• †Euphemites
  • †Euphemites lentiformis
  • †Euphemites urei
• †Euprimitia
  • †Euprimitia celata
  • †Euprimitia flores
  • †Euprimitia labiosa
  • †Euprimitia linepunctata
  • †Euprimitia minuta
  • †Euprimitia sanctipauli
• †Euptychocrinus
  • †Euptychocrinus skopaios
• †Eurychilina
  • †Eurychilina incurva
  • †Eurychilina minutifoveata
  • †Eurychilina partifimbriata
  • †Eurychilina reticulata
  • †Eurychilina subradiata
  • †Eurychilina ventrosa
• †Eutaxocrinus
  • †Eutaxocrinus gracilis
• †Exocrinus
  • †Exocrinus multirami

• †Fardenia – tentative report
• †Favosites
• †Fenestella
• †Fenestrellina
• †Ferganella
• †Fistulipora
• †Flabellitesia
  • †Flabellitesia flabellites

• 

  †Flexicalymene
• †Floweria
  • †Floweria altirostris
  • †Floweria orthoplicata
  • †Floweria prava
• †Floyda
  • †Floyda concentrica
• †Fourstonella

• †Galateacrinus
  • †Galateacrinus gossameri
• †Gilmocrinus
• †Girtyella
  • †Girtyella indianse
• †Glabrocingulum
  • †Glabrocingulum angulosa – type locality for species
  • †Glabrocingulum minutum – type locality for species
• †Glaphyrites
• †Glossites
• †Glyptorthis
  • †Glyptorthis pulchra – type locality for species
  • †Glyptorthis subcircularis – type locality for species
• †Gomphocystites

• 

  †Goniatites
• †Goniocrinus
• †Goniophyllum
  • †Goniophyllum pyramidale
• †Gorgonophontes
  • †Gorgonophontes peleron
• †Graffhamicrinus
  • †Graffhamicrinus magnijkus
  • †Graffhamicrinus subcoronatus
• †Grammysia
  • †Grammysia amygdalinus
• †Gravicalymene
• †Greenops
  • †Greenops barrisi
  • †Greenops fitzpatricki

• 

  †Grewingkia
• †Gypidula
  • †Gypidula cornuta
  • †Gypidula munda
  • †Gypidula occidentalis
  • †Gypidula papyracea
  • †Gypidula parva
• †Gypidulina
• †Gyroceras

• †Hadrorhynchia
  • †Hadrorhynchia solon
• †Haeretocrinus
  • †Haeretocrinus missouriensis
• †Hagnocrinus
• †Hallatia
  • †Hallatia convexa
  • †Hallatia duplicata
  • †Hallatia particylincrica
  • †Hallatia particylindrica
• †Hallicystis
• †Halliella
  • †Halliella magnipunctata

• 

  †Hallopora
• †Halysiocrinus
  • †Halysiocrinus barrisi
  • †Halysiocrinus elephantinus – type locality for species
• †Halysites
• †Hammatostroma
  • †Hammatostroma albertense
• †Harpidella – tentative report
  • †Harpidella brandonensis
• †Harpidium
  • †Harpidium luckeyensis – or unidentified related form
  • †Harpidium maquoketa
• †Hedeina
• †Heliolites

• 

  †Heliophyllum
  • †Heliophyllum solidum
• †Helliella
  • †Helliella magnipunctata
• †Hemicystites
• †Hemiphragma
• †Hemiplethorhynchus
  • †Hemiplethorhynchus subovatum
• †Hermatostroma
  • †Hermatostroma polymorphum
• †Hernodia
• †Hesperidella
  • †Hesperidella initialis

• 

  †Hexagonaria
  • †Hexagonaria bassleri
  • †Hexagonaria inequalis
  • †Hexagonaria oweni
  • †Hexagonaria whitfieldi
• †Hibbardella
  • †Hibbardella subacoda
• †Hindella
• †Hindia
  • †Hindia parva – tentative report
  • †Hindia sphaeroidalis
• †Holcocrinus

• 

  †Holopea
  • †Holopea iowaensis
• †Homacanthus
  • †Homacanthus delicatulus
• †Homoeospira
• †Homotrypella
• †Hormotoma
  • †Hormotoma gracilis
• †Howellella
• †Hudsonaster
• †Huronia
• †Hustedia
• †Hyattidina
• †Hybocrinus
  • †Hybocrinus conicus

†Hyolithes

• • †Hyolithes parviusculus
• †Hypergonia
  • †Hypergonia percarinata
• †Hypothyridina
  • †Hypothyridina emmonsi
  • †Hypothyridina intermedia
  • †Hypothyridina magister
• †Hypselocrinus
• †Hypsitycha
  • †Hypsitycha hybrida
• †Hysitycha
  • †Hysitycha neenah
• †Hystriculina

• †Ianthinopsis
  • †Ianthinopsis pinguis – type locality for species
• †Icriodus
  • †Icriodus calvini – type locality for species
  • †Icriodus latericrescens
  • †Icriodus nodosus
  • †Icriodus orri – type locality for species
  • †Icriodus subterminus
• †Icthyocrinus
• †Idiognathodus
  • †Idiognathodus attenuatus – type locality for species
  • †Idiognathodus claviformis
  • †Idiognathodus iowaensis – type locality for species
• †Ignoceras
  • †Ignoceras undata
• †Indospirifer
  • †Indospirifer orestes

• 

  †Iniopteryx
  • †Iniopteryx rushlaui
  • †Iniopteryx tedwhitei
• †Iocrinus
• †Iowacystis
  • †Iowacystis sagittaria
• †Iowaphyllum
  • †Iowaphyllum johanni
• †Iowatrypa
  • †Iowatrypa americana
  • †Iowatrypa owenensis
• †Ischadites
• †Isorthis
• †Isorthoceras
  • †Isorthoceras sociale

• 

  †Isotelus

• †Juresania

• †Kaskia
• †Kayoceras
• †Kiesowia
  • †Kiesowia binoda
  • †Kiesowia insolens
• †Kinocrinus
  • †Kinocrinus inflatus

• 

  †Kionoceras
  • †Kionoceras decorahense – type locality for species
• †Kirkidium
• †Kitikamispira – tentative report
  • †Kitikamispira perstrialis – type locality for species
• †Knightella
  • †Knightella shumardiana – type locality for species
• †Kosovopeltis
  • †Kosovopeltis acamas
• †Krausella
  • †Krausella arcuata
  • †Krausella curtispina
  • †Krausella inaequalis
• †Krinocrinus
  • †Krinocrinus inflatus

• †Laccoprimitia
  • †Laccoprimitia elegantula
  • †Laccoprimitia fillmorensis
• †Lacertasterias – type locality for genus
  • †Lacertasterias elegans – type locality for species
• †Laddella
  • †Laddella insueta
• †Ladogioides
  • †Ladogioides solon
• Laevidentalium
• †Lamottia
  • †Lamottia heroensis
• †Lampterocrinus
• †Lanecrinus – tentative report
• †Leangella
• †Lecanocrinus
• †Lecathylus
  • †Lecathylus gregarius
• †Lechritochoceras
• †Leioclema
  • †Leioclema occidens
• †Leiorhynchus
  • †Leiorhynchus argenteum
  • †Leiorhynchus gosseleti
  • †Leiorhynchus iris
• †Leperditella
  • †Leperditella dorsicornis
  • †Leperditella fryei
  • †Leperditella macra
  • †Leperditella millepunctata
  • †Leperditella persimilis
  • †Leperditella sacceliformis
• †Leperditia
• †Lepidocyclus
• †Lepidoleptaena – or unidentified related form
• †Leptaena
  • †Leptaena rhomboidalis
• †Leptagonia
  • †Leptagonia analoga
• †Leptellina
• †Leptobolus
  • †Leptobolus occidentalis
• †Leptodesma
  • †Leptodesma acutilaris
  • †Leptodesma subovata
• †Leptopora
  • †Leptopora typa
• †Leptoptygma
  • †Leptoptygma oligospira – type locality for species
• †Leptostrophia – tentative report
• †Leptotrypella
• †Lichenalia
• †Lichenocrinus

• 

  †Lingula
  • †Lingula changi
  • †Lingula cuneata
  • †Lingula fragila
  • †Lingula milwaukeensis – or unidentified comparable form
  • †Lingula milwaukiensis
• †Lingulodiscina
  • †Lingulodiscina marginalis
• †Linocrinus
• †Linoporella
• †Linoproductus
  • †Linoproductus ovatus
• †Liospira
  • †Liospira micula
  • †Liospira spicula – or unidentified comparable form
• †Litostrobus
  • †Litostrobus iowensis
  • †Litostrobus paulus
• †Lonchodus – tentative report
• †Lophophyllidium
• †Lophospira
  • †Lophospira depauperata
• †Lorangerella
  • †Lorangerella gregaria
• †Loxonema
• †Lumbriconereites
• †Luxocrinus
  • †Luxocrinus simplex
• †Lyonicrinus
• †Lyriocrinus
• †Lysocystites
  • †Lysocystites nodosus
• †Lytospira

• †Macgeea
  • †Macgeea camplanulata – type locality for species
  • †Macgeea concinnula – type locality for species
  • †Macgeea culmula
  • †Macgeea solitaria
• †Macrocrinus
  • †Macrocrinus mundulus
• Macrocypris
  • †Macrocypris kayi
• †Macrocyproides
  • †Macrocyproides clermontensis
• †Macronotella
  • †Macronotella arcta
  • †Macronotella scofeldi
  • †Macronotella scofieldi
• †Macropotamorhynchus
  • †Macropotamorhynchus tuta
• †Macrostylocrinus
  • †Macrostylocrinus compressus
  • †Macrostylocrinus obpyramidalis – or unidentified comparable form
  • †Macrostylocrinus vermiculatus
• †Manicrinus

• 

  †Manticoceras
  • †Manticoceras regulare
• †Manticrinus
• †Maquoketacrinus
  • †Maquoketacrinus ornatus
• †Maratia
  • †Maratia mara
  • †Maratia micula
• †Marsupiocrinus
  • †Marsupiocrinus primaevus
• †Mediospirifer
• †Megalomoidea
• †Megamyonia
  • †Megamyonia unicostata
• †Megastrophia
  • †Megastrophia profunda
• †Megistocrinus
  • †Megistocrinus pernodosus
• †Melocrinites
• †Merista

• 

  †Meristella
  • †Meristella parva
• †Meristina
• †Merocrinus
• †Mesoblastus – or unidentified comparable form
• †Mesolobus
• †Metaconularia
• †Metalonchodina
  • †Metalonchodina deflecta – type locality for species
• †Michelia
• †Michelinoceras
• †Microcardinalia
• †Milleratia
  • †Milleratia cincinnatiensis
  • †Milleratia cincinnattiensis
• †Mirifusella – type locality for genus
  • †Mirifusella fortunata – type locality for species
• †Modiomorpha
• †Monomerella
• †Murchisonia
• †Myalina
• †Mycterops
  • †Mycterops whitei – type locality for species
• †Myeinocystites
• †Myelodactylus
• †Mystrocephala
  • †Mystrocephala pulchra – or unidentified comparable form
  • †Mystrocephala raripustulosus
• †Mytilarca

• †Nactocrinus
• †Nalivkinia – tentative report
• †Nataliana – type locality for genus
  • †Nataliana sinuata – type locality for species

• 

  †Naticopsis
  • †Naticopsis depressa – type locality for species
• †Neopanderodus
• †Neospirifer
• †Neozaphrentis
  • †Neozaphrentis pellaensis
• †Nervostrophia
  • †Nervostrophia calvini
  • †Nervostrophia canace
  • †Nervostrophia contaderoensis
  • †Nervostrophia extensa
  • †Nervostrophia multinervosa
  • †Nervostrophia rockfordensis
  • †Nervostrophia solida
  • †Nervostrophia thomasi
• †Newberria
  • †Newberria cordiforme
  • †Newberria johanni
• †Ningulella
  • †Ningulella paucisulcata
• †Nodambichilina
  • †Nodambichilina symmetrica
• †Nucellangium
  • †Nucellangium glabrum
• †Nucleospira
  • †Nucleospira barrisi

• 

  Nucula
  • †Nucula glanparkensis
  • †Nucula iowensis
• Nuculana
  • †Nuculana sacata
• †Nuculites
  • †Nuculites neglectus
• †Nuculopsis

• †Odontopleura
• †Oepikina
• †Oistodus
  • †Oistodus venustus
• †Onniella
  • †Onniella quadrata

• 

  †Onychodus
• †Opikatia
  • †Opikatia emaciata
  • †Opikatia rotunda
• †Opoa
• †Orbiculoidea
  • †Orbiculoidea telleri
  • †Orbiculoidea varsoviensis
  • †Orbiculoidea wardi
• †Orecopia
  • †Orecopia circinatus – type locality for species
• †Oriostoma
• †Orthoceras
  • †Orthoceras indianense
• †Orthodesma
• †Orthograptus
  • †Orthograptus eucharis
  • †Orthograptus truncatus
• †Orthonychia
  • †Orthonychia vomerium
• †Orthospirifer
  • †Orthospirifer capax
  • †Orthospirifer euruteines
  • †Orthospirifer iowensis
  • †Orthospirifer parryanus
• †Orthotetes
  • †Orthotetes kaskaskiensis
• †Otarion – tentative report
• †Oulodus
  • †Oulodus abbreviata – type locality for species
  • †Oulodus serratus
• †Ovatia
  • †Ovatia laevicostata
  • †Ovatia ovata
• †Ozarkodina
  • †Ozarkodina campbelli – type locality for species
  • †Ozarkodina delicatula
  • †Ozarkodina raaschi

• †Pachyphyllum
  • †Pachyphyllum crassicostatum
  • †Pachyphyllum dumonti – type locality for species
  • †Pachyphyllum gregarium
  • †Pachyphyllum minutissimum
  • †Pachyphyllum websteri
  • †Pachyphyllum woodmani
• †Paladin
  • †Paladin wilsoni
• †Palaeocapulus
  • †Palaeocapulus equilateralis
• †Palaeoconcha
• †Palaeocyclus
• †Palaeoneilo
  • †Palaeoneilo barrisi
  • †Palaeoneilo fecunda
• †Palaeostachys
  • †Palaeostachys andrewsii
• †Palaeozygopleura
  • †Palaeozygopleura difficile
• †Palmatolepis
  • †Palmatolepis foliacea
  • †Palmatolepis semichatovae
• †Panderous
  • †Panderous gracilis
  • †Panderous panderi
• †Parabolbina
  • †Parabolbina antecedans
  • †Parabolbina carinifera
  • †Parabolbina staufferi
• †Paracosmetocrinus
• †Paracyclas
  • †Paracyclas dubia
  • †Paracyclas dubius
  • †Paracyclas elliptica
  • †Paracyclas parvula
  • †Paracyclas paucipleura
  • †Paracyclas proavia
  • †Paracyclas sabini
  • †Paracyclas validalinea
  • †Paracyclas validelinea
• †Paraphorhynchus
  • †Paraphorhynchus elongatum
  • †Paraphorhynchus striatocostatum
• †Paraschmidtella
  • †Paraschmidtella irregularis
  • †Paraschmidtella uphami
• †Parenthatia
  • †Parenthatia camerata
  • †Parenthatia punctata
• †Patellilabia
  • †Patellilabia scriptiferus
• †Paucicrura
  • †Paucicrura corpulenta
• †Paupospira

• 

  †Peachocaris
  • †Peachocaris acanthouraea – type locality for species
• †Pedomphalella
  • †Pedomphalella intermedia
  • †Pedomphalella subovata
• †Pentamerella
  • †Pentamerella dubia
  • †Pentamerella laeviscula
  • †Pentamerella laeviuscula
  • †Pentamerella magna
  • †Pentamerella multicostella
  • †Pentamerella obsolescens
  • †Pentamerella rugosa
  • †Pentamerella subarata
• †Pentameroides
  • †Pentameroides corrugatus
  • †Pentameroides subrectus

• 

  †Pentamerus
  • †Pentamerus oblongus
• †Pentlandina
• †Pentremites
  • †Pentremites pulchellus
• †Perditocardinia
  • †Perditocardinia iowensis – type locality for species
• †Periechocrinus
• †Pernopecten
  • †Pernopecten cooperensis
• †Petalocrinus
  • †Petalocrinus mirabilis

• 

  †Petalodus
  • †Petalodus allegheniensis
• †Petalotrypa
  • †Petalotrypa formosa
• †Petrocrania
  • †Petrocrania famelica
  • †Petrocrania familica
• †Petrodus
  • †Petrodus patelliformis
• †Phacops
  • †Phacops iowensis
• †Phanerotrema
• †Philhedra
  • †Philhedra sheldoni
• †Phillipsia
• †Phoebodus
  • †Phoebodus densneptuni – type locality for species
• †Pholidostrophia
  • †Pholidostrophia iowensis
• †Phragmoceras
• †Phragmodus
  • †Phragmodus cognitus
  • †Phragmodus undatus
• †Phricodothyris
• †Phymatopleura
• †Physonemus
  • †Physonemus hamuspiscatorius
  • †Physonemus pandatus
• †Piloricilla
  • †Piloricilla sedaliensis
• †Pinnocaris
  • †Pinnocaris americana – type locality for species
• †Pisocrinus

• 

  †Plaesiomys
  • †Plaesiomys subquadrata
• †Plagioglypta
  • †Plagioglypta iowaensis
• †Planalvus – type locality for genus
  • †Planalvus gibberosa – type locality for species
• †Plasmopora
• †Platyceras
  • †Platyceras antiquum
  • †Platyceras insolitum
  • †Platyceras irrasum
  • †Platyceras latum – tentative report
  • †Platyceras nasutum
  • †Platyceras paralium

• 

  †Platycrinites
• †Platycrinus
• †Platylichas
• †Platyrachella
  • †Platyrachella ballardi
  • †Platyrachella macbridei
• †Platyschisma
  • †Platyschisma barrisi
  • †Platyschisma depressa
  • †Platyschisma laudoni – type locality for species
• †Platystrophia
  • †Platystrophia biforata
• †Plectatrypa
• †Plectodina
  • †Plectodina aculeata
• †Plectodonta
  • †Plectodonta produla

• 

  †Pleurocystites
  • †Pleurocystites beckeri
  • †Pleurocystites filitextus – tentative report
  • †Pleurocystites strimplei
• Pleurotomaria – tentative report
  • †Pleurotomaria verticillata
• †Plicochonetes
• †Plicostricklandia
• †Podolithus
• †Poleumita
• †Polusocrinus
  • †Polusocrinus rosa

• 

  †Polygnathus
  • †Polygnathus decorosus
  • †Polygnathus intermedius
  • †Polygnathus parawebbi
  • †Polygnathus xylus
• †Polyplacognathus
  • †Polyplacognathus ramosus
• †Polytryphocycloides
• †Polytylites
  • †Polytylites wilsoni
• †Porcellia
  • †Porcellia crassinoda
  • †Porcellia obliquinoda
  • †Porcellia rectinoda – type locality for species
• †Porocrinus
  • †Porocrinus crassus
  • †Porocrinus fayettensis
  • †Porocrinus pentagonius
• †Porpites
• †Posidonia
• †Praecupulocrinus
  • †Praecupulocrinus conjugans
• †Praenucula – tentative report
• †Praewaagenoconcha
  • †Praewaagenoconcha speciosa
• †Prasopora
• †Prasoporina
• †Pregazacrinus
  • †Pregazacrinus hemisphericus
• †Primitia
  • †Primitia gibbera
  • †Primitia spinata
• †Primitiella
  • †Primitiella bellevuensis
  • †Primitiella carlei
  • †Primitiella constricta
  • †Primitiella milleri
  • †Primitiella plattevillensis
• †Primitiopsis – tentative report
  • †Primitiopsis bella
• †Primitopsis – tentative report
  • †Primitopsis bella
• †Priscella
• †Probillingsites
• †Productella
  • †Productella belanskii
  • †Productella camerata
  • †Productella fragilis
  • †Productella iowa
  • †Productella linnensis
  • †Productella perplana
  • †Productella rugatula
  • †Productella sericea
  • †Productella subaculeata
  • †Productella subalata
  • †Productella thomasi
• †Productus
  • †Productus arcuatus
  • †Productus ovatus
  • †Productus sedaliensis
• †Proetides
  • †Proetides insignis

• 

  †Proetus
  • †Proetus channahonensis – or unidentified comparable form
• †Promexyele
  • †Promexyele peyeri
• †Prospira
  • †Prospira greenockensis – or unidentified related form
  • †Prospira legrandensis
• †Protacrocrinus
• †Protatrypa
• †Protaxocrinus
• †Protoleptostrophia
  • †Protoleptostrophia fragilis
• †Protomegastrophia
• †Protometgastrophia
• †Protoniella
  • †Protoniella parva
• †Protoscolex
• †Pseudoammodiscus
• †Pseudoatrypa
  • †Pseudoatrypa bentonensis
  • †Pseudoatrypa blackhawkensis
  • †Pseudoatrypa boyeri – or unidentified comparable form
  • †Pseudoatrypa bremerensis
  • †Pseudoatrypa devoniana
  • †Pseudoatrypa minor
  • †Pseudoatrypa percrassa
  • †Pseudoatrypa rotunda
  • †Pseudoatrypa rugatula
• †Pseudobelodina – tentative report
• †Pseudoconocardium
• †Pseudoglomospira
• †Pseudopalmula
  • †Pseudopalmula palmuloides
• †Pseudoplagiothyra
  • †Pseudoplagiothyra praecursor
• †Pseudozygopleura
• †Pseudulrichia
  • †Pseudulrichia simplex
• †Pterinea
• †Ptychophyllum
• †Ptychopleurella
  • †Ptychopleurella bouchardi – or unidentified comparable form
• †Ptychopteria
  • †Ptychopteria chemungensis
• †Ptyctodopsis – type locality for genus
  • †Ptyctodopsis menzeli – type locality for species

• 

  †Ptyctodus
• †Pugnoides
  • †Pugnoides calvini
  • †Pugnoides ottumwa
• †Punctaparchites
  • †Punctaparchites rugosus
  • †Punctaparchites splendens
• †Punctospirifer
  • †Punctospirifer solidirostris
• †Pycnostylus
• †Pyramiblastus
  • †Pyramiblastus fusiformis – type locality for species
• †Pyrgocystis

• †Quasibollia
  • †Quasibollia ridicula
• †Quienquecaudex
  • †Quienquecaudex springeri

• †Raphistomina
• †Raymondatia
  • †Raymondatia goniglypta
  • †Raymondatia gonigplyta
• †Raymondiata
  • †Raymondiata goniglypta
• †Resserella
• †Retichonetes
  • †Retichonetes brandonensis
• †Reticularia
  • †Reticularia cooperensis
• †Retispira
  • †Retispira bilabiatus
  • †Retispira deflectus
  • †Retispira exilis
  • †Retispira perelegans
  • †Retispira type locality for species Kues & Batten 2001 – informal
• †Rhaphanocrinus
• †Rhaphistomina
• †Rhineoderma
  • †Rhineoderma dinglensis
• †Rhipidium
• †Rhipidomella
  • †Rhipidomella cuneata
  • †Rhipidomella dalyana – or unidentified comparable form
  • †Rhipidomella tenuicostata
  • †Rhipidomella thiemei
• †Rhodocrinites
• †Rhombopora
• †Rhynchodus
• †Rhynchopora
  • †Rhynchopora pustulosa
  • †Rhynchopora rowleyi
• †Rhynchotrema
• †Rhynchotreta
• †Rhyssochonetes
  • †Rhyssochonetes bellarugosis
• †Rigidella
• †Ripidiorhynchus
  • †Ripidiorhynchus cedarensis
• †Rugosochonetes
  • †Rugosochonetes multicastatus

• †Saccelatia
  • †Saccelatia angularis
  • †Saccelatia arcuamuralis
  • †Saccelatia arrecta
  • †Saccelatia bullata
  • †Saccelatia cletifera
• †Sanguinolites
• †Scaphelasma
• †Schellwienella
  • †Schellwienella crenulicostata
  • †Schellwienella inaequalis
  • †Schellwienella inflata
  • †Schellwienella planumbona
• †Schizoblastus
  • †Schizoblastus roemeri
• †Schizodus
  • †Schizodus sedaliensis
  • †Schizodus trigonalis
• †Schizophoria
  • †Schizophoria amanaensis
  • †Schizophoria athabaskensis – or unidentified related form
  • †Schizophoria athabaskiensis – or unidentified related form
  • †Schizophoria chouteauensis
  • †Schizophoria dorsata
  • †Schizophoria floydensis
  • †Schizophoria floydia
  • †Schizophoria impressa
  • †Schizophoria iowensis
  • †Schizophoria landoni
  • †Schizophoria lata
  • †Schizophoria laudoni
  • †Schizophoria macfarlanei
  • †Schizophoria macfarlanii
  • †Schizophoria minor
  • †Schizophoria multistriata
  • †Schizophoria subelliptica
• †Schmidtella
  • †Schmidtella affinis
  • †Schmidtella brevis
  • †Schmidtella lacunosa
  • †Schmidtella latimarginata
• †Schuchertella
  • †Schuchertella acutistriata
  • †Schuchertella altirostris
  • †Schuchertella humboldtensis
  • †Schuchertella iowensis
  • †Schuchertella nodocostata
  • †Schuchertella parva
  • †Schuchertella pectiniformis
• †Scofielda
  • †Scofielda bilateralis
• †Scofieldia
  • †Scofieldia bilateralis
• †Scutellum
  • †Scutellum depressum
  • †Scutellum thomasi

• 

  †Scytalocrinus
• †Selenella
  • †Selenella pediculus
• †Semitextularia
  • †Semitextularia thomasi
• †Septemchiton
  • †Septemchiton iowaensis
  • †Septemchiton iowensis
• †Septopora
• †Serpulospira
  • †Serpulospira paradoxus – type locality for species
• †Setigerites
• †Shumardella
• †Sieberella – tentative report
  • †Sieberella insolita
• †Sievertsia
• †Sigournea – type locality for genus
  • †Sigournea multidentata – type locality for species
• †Similodonta
  • †Similodonta obliqua
• †Simulodonta
  • †Simulodonta obliqua
• †Sinuites
  • †Sinuites subcompressa
• †Siphonocrinus
  • †Siphonocrinus nobilis
• †Skenidioides – tentative report
• †Skenidium
  • †Skenidium independense
• †Smithiphyllum
  • †Smithiphyllum belanskii
• †Sowerbyella
• †Spathella
• †Sphaerirhynchia

• 

  †Sphenothallus
• †Spinatrypa
  • †Spinatrypa aspera
  • †Spinatrypa augusticostata – or unidentified comparable form
  • †Spinatrypa bellula
  • †Spinatrypa borealis
  • †Spinatrypa hystrix
  • †Spinatrypa mascula
  • †Spinatrypa occidentalis
  • †Spinatrypa planosulcata
  • †Spinatrypa rockfordensis
  • †Spinatrypa trulla
• †Spinatrypina
  • †Spinatrypina angusticostata – or unidentified comparable form
  • †Spinatrypina edmundsi
• †Spinocarinifera
  • †Spinocarinifera arcuata
  • †Spinocarinifera arcuatus
• †Spinocyrtia
  • †Spinocyrtia alta
  • †Spinocyrtia ballardi
  • †Spinocyrtia capax
  • †Spinocyrtia cedarensis
  • †Spinocyrtia corvirostra
  • †Spinocyrtia curvirostra
  • †Spinocyrtia cyrtiformis
  • †Spinocyrtia cyrtinaformis
  • †Spinocyrtia iowensis
  • †Spinocyrtia macbridei
  • †Spinocyrtia pulchra
  • †Spinocyrtia westerensis
• †Spinulicosta
  • †Spinulicosta spinulicosta

• 

  †Spirifer
  • †Spirifer biplicoides
  • †Spirifer forbesi
  • †Spirifer gregeri
  • †Spirifer legrandensis
  • †Spirifer louisianensis
  • †Spirifer marshallensis
  • †Spirifer missouriensis
  • †Spirifer orestes
  • †Spirifer platynotus
  • †Spirifer stratiformis
• †Spiriferina
  • †Spiriferina solidirostris
  • †Spiriferina solidirostrus
  • †Spiriferina subtexta
• †Spirinella
• Spirorbis
• †Spyroceras
• †Stachyodes
  • †Stachyodes costulata
• †Stainbrookia
  • †Stainbrookia infera
• †Staufferella
  • †Staufferella falcata
• †Stegocoelia
  • †Stegocoelia quadricincta – type locality for species
• †Stenopareia
  • †Stenopareia slocomi – or unidentified comparable form
• †Stenopareiea
• †Stephanocrinus
• †Stereostylus
  • †Stereostylus aages – type locality for species

• 

  †Stethacanthus
  • †Stethacanthus depressus
  • †Stethacanthus erectus
• †Stictopora
• †Stictostroma
  • †Stictostroma ordinarium
• †Straparollus
  • †Straparollus ammon
  • †Straparollus argutus – type locality for species
  • †Straparollus cyclostomus
  • †Straparollus macromphalus
• †Streptelasma
  • †Streptelasma trilobatum – or unidentified comparable form
• †Streptis
• †Streptognathodus
  • †Streptognathodus delicatulus – type locality for species
  • †Streptognathodus symmetricus – type locality for species
• †Streptorhynchus
  • †Streptorhynchus tenuicostatum
• †Striatochonetes
  • †Striatochonetes buchananensis
  • †Striatochonetes schucherti
• †Striatopora
  • †Striatopora iowensis
• †Stricklandia
  • †Stricklandia laevis
  • †Stricklandia lens
• †Striispirifer
• †Strimplecrinus
• †Strobilocystites
• †Stromatopora
• †Strophalosia
• †Strophodonta
  • †Strophodonta umbonata
• †Stropholosia
  • †Stropholosia littletonensis

• 

  †Strophomena
  • †Strophomena abnormalis
  • †Strophomena biplacata
  • †Strophomena cedarensis
  • †Strophomena cicatricosa
  • †Strophomena costata
  • †Strophomena dorsata
  • †Strophomena erratica
  • †Strophomena halli
  • †Strophomena iowensis
  • †Strophomena linderi
  • †Strophomena littleonensis
  • †Strophomena littletonensis
  • †Strophomena masonensis
  • †Strophomena mineolaensis
  • †Strophomena nortoni
  • †Strophomena parva
  • †Strophomena perarcuata
  • †Strophomena planodorsata
  • †Strophomena plicata
  • †Strophomena quadratella
  • †Strophomena randalia
  • †Strophomena reticulata
  • †Strophomena scottensis
  • †Strophomena solonensis
  • †Strophomena subdemissa
  • †Strophomena thomasi
  • †Strophomena trilobata – type locality for species
  • †Strophomena unbonata
  • †Strophomena vera
• †Strophonella
• †Strophonelloides
  • †Strophonelloides reversa
• †Strophostylus
  • †Strophostylus bivolve
• †Stylonema – tentative report
• †Sublobalocrinus
  • †Sublobalocrinus kasseri
• †Sulcatostrophia
  • †Sulcatostrophia camerata
  • †Sulcatostrophia euglyphea
• †Sygcaulocrinus
  • †Sygcaulocrinus typus

• 

  †Syringopora
• †Syringostroma – tentative report
  • †Syringostroma confertum
• †Syringothyris
  • †Syringothyris halli
  • †Syringothyris hannibalensis
  • †Syringothyris newarkensis

• †Tabulophyllum
  • †Tabulophyllum buccinum – type locality for species
  • †Tabulophyllum curtum – type locality for species
  • †Tabulophyllum ehlersi
  • †Tabulophyllum ellipticum
  • †Tabulophyllum expansum
  • †Tabulophyllum levorsoni – type locality for species
  • †Tabulophyllum longum
  • †Tabulophyllum magnum
  • †Tabulophyllum mutabile – type locality for species
  • †Tabulophyllum ponderosum
  • †Tabulophyllum rectum
  • †Tabulophyllum robustum
  • †Tabulophyllum rotundum
  • †Tabulophyllum solidum
• †Tanaocystis
  • †Tanaocystis type locality for species – informal
• †Tarphyphyllum
  • †Tarphyphyllum cylindricum – type locality for species

• 

  †Taxocrinus
• †Tecnocyrtina
  • †Tecnocyrtina curvilineata
  • †Tecnocyrtina missouriensis
• †Tenticospirifer
  • †Tenticospirifer cyrtinaeformis
  • †Tenticospirifer cyrtinaformis
  • †Tenticospirifer shellrockensis
• †Tetradella
  • †Tetradella carinata
  • †Tetradella ellipsilira
  • †Tetradella septinoda
  • †Tetradella subquadrans
  • †Tetradella ulrichi
• †Teutonophon
  • †Teutonophon tangentialis
• †Thaerodonta
  • †Thaerodonta recedens
• †Thalamocrinus
• †Theleproktocrinus
  • †Theleproktocrinus davidsoni
• †Theodissa
  • †Theodissa hungerfordi
• †Theodossia
  • †Theodossia hungerfordi
• †Thomasaria
  • †Thomasaria altumbona
• †Thomasatia
  • †Thomasatia falcicosta
• †Thomasocrinus
  • †Thomasocrinus cylindrica
• †Timeischytes
• †Torynifer
• †Trachydomia
  • †Trachydomia variata
• †Tranodis
• †Trapezophyllum
• †Tremanotus
• †Trichinocrinus
• †Trigeria
• †Trimerella
• †Triplesia
• †Trochonema
• †Tropidodiscus
• †Trupetustroma
  • †Trupetustroma bassleri
  • †Trupetustroma hayense
• †Tubisalebra
• †Turbonopsis
  • †Turbonopsis hackberryensis
  • †Turbonopsis spiculatus – type locality for species
• †Tylothyris
  • †Tylothyris bimesialis
  • †Tylothyris inultilis
  • †Tylothyris megista
  • †Tylothyris mesacostalis
  • †Tylothyris rockfordensis
  • †Tylothyris subattenuatta
  • †Tylothyris subvaricosa
  • †Tylothyris sulcocostata

• †Ulocrinus
• †Ulrichia
  • †Ulrichia saccula
• †Unispirifer
  • †Unispirifer minnewankensis – or unidentified comparable form
  • †Unispirifer platynotus

• †Variatrypa
  • †Variatrypa arctica
  • †Variatrypa lineata
  • †Variatrypa rugatula
• †Verkhotomia – tentative report
  • †Verkhotomia calvini

• †Waagenella
  • †Waagenella sowerbyi – tentative report
• †Warrenella
  • †Warrenella extensa
• †Warthia
• †Wellerella
• †Westerna
  • †Westerna gigantea
• †Whatcheeria – type locality for genus
  • †Whatcheeria deltae – type locality for species
• †Whidbornella
  • †Whidbornella lachrymosa
• †Whitfieldella
• †Winchellatia
  • †Winchellatia lansingensis
  • †Winchellatia longispina
  • †Winchellatia minnesotensis
• †Worthenia

• †Youngia

• †Zaphrenthis
  • †Zaphrenthis calceola
  • †Zaphrenthis cliffordana
• †Zygobolboides
  • †Zygobolboides calvini
  • †Zygobolboides grafensis
  • †Zygobolboides iowensis
  • †Zygobolboides thomasi
• †Zygospira
  • †Zygospira resupinata

• Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Retrieved December 17, 2021.